Detalhes

Two new species discovered by CEB researchers

December 01, 2006

Braga

1. Aspergillus ibericus

Fungi are among the most abundant and simultaneously less known organisms in the planet. The magnitude of fungal diversity was estimated conservatively at 1,5 million species, of which only 10% are known to science. Researchers from CEB (Rita Serra and Armando Venâncio) in cooperation with researchers from 3 countries (Spain, Italy and UK) members of a European Project to prevent the formation of a fungal toxin (ochratoxin A) in wines, found a new Aspergillus species, Aspergillus ibericus, when studying the fungi of Portuguese grapes. This species is part of a group of organisms with strong biotechnological interest as it is capable of producing enzymes of industrial interest and its potential uses are in progress.

More recently another 3 new species were found in grapes and 6 more from cork bark of the genus Penicillium, in cooperation with Dr. Stephen Peterson of the U.S. Department of Agriculture (USDA), which formal description is being undertaken. These discoveries show that the Mediterranean cultures from Portugal are a very interesting source of unknown biodiversity yet to be explored. It is the first time that Portuguese scientists find new species in these genera, of utmost importance in the discovery of new enzymes and bioactive molecules with pharmaceutical interest.

2. Syntrophomonas zehnderiAnaerobic digestion of long chain fatty acids (LCFA)-based effluents is one of the main subjects of research at the BRIDGE group, Centre of Biological Engineering, University of Minho (Portugal). These pollutant compounds, commonly present in wastewaters from food processing industries, can be used as energetic resources for the production of biogas, a renewable source of energy. In its essence, the energetic valorization of LCFA-based wastewaters in anaerobic bioreactors relies on the biological performance of the syntrophic communities responsible for their conversion to biogas. Recently, a new obligate syntrophic fatty acid degrading bacterium, Syntrophomonas zehnderi was isolated from a mesophilic expanded granular sludge bed (EGSB) reactor treating an oleate-based effluent (oleate is one of the most abundant LCFA in wastewaters). This bacterium can use LCFA in co-culture with a hydrogen-consuming archaea, and it is the third acetogenic bacterium to be isolated with the capability of degrading unsaturated LCFA (i.e. LCFA containing one or more double bonds within the carbon chain). This work was developed in cooperation with Prof Alfons Stamsand Dr Hauke Smidt from the Laboratory of Microbiology, Wageningen University (The Netherlands), and it is on-going with the recently accepted project for genome sequencing of Syntrophomonas zehnderi by DOE-Joint Genome Institute (USA). Further studies on the genomic and proteomic levels will certainly improve our knowledge on the physiology and biochemical mechanisms of syntrophic LCFA degradation.